diff options
Diffstat (limited to 'arch/s390/mm/pgtable.c')
| -rw-r--r-- | arch/s390/mm/pgtable.c | 1207 |
1 files changed, 1207 insertions, 0 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c new file mode 100644 index 000000000..5cb929415 --- /dev/null +++ b/arch/s390/mm/pgtable.c @@ -0,0 +1,1207 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright IBM Corp. 2007, 2011 + * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> + */ + +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/gfp.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/smp.h> +#include <linux/spinlock.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> +#include <linux/swapops.h> +#include <linux/sysctl.h> +#include <linux/ksm.h> +#include <linux/mman.h> + +#include <asm/tlb.h> +#include <asm/tlbflush.h> +#include <asm/mmu_context.h> +#include <asm/page-states.h> + +pgprot_t pgprot_writecombine(pgprot_t prot) +{ + /* + * mio_wb_bit_mask may be set on a different CPU, but it is only set + * once at init and only read afterwards. + */ + return __pgprot(pgprot_val(prot) | mio_wb_bit_mask); +} +EXPORT_SYMBOL_GPL(pgprot_writecombine); + +pgprot_t pgprot_writethrough(pgprot_t prot) +{ + /* + * mio_wb_bit_mask may be set on a different CPU, but it is only set + * once at init and only read afterwards. + */ + return __pgprot(pgprot_val(prot) & ~mio_wb_bit_mask); +} +EXPORT_SYMBOL_GPL(pgprot_writethrough); + +static inline void ptep_ipte_local(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, int nodat) +{ + unsigned long opt, asce; + + if (MACHINE_HAS_TLB_GUEST) { + opt = 0; + asce = READ_ONCE(mm->context.gmap_asce); + if (asce == 0UL || nodat) + opt |= IPTE_NODAT; + if (asce != -1UL) { + asce = asce ? : mm->context.asce; + opt |= IPTE_GUEST_ASCE; + } + __ptep_ipte(addr, ptep, opt, asce, IPTE_LOCAL); + } else { + __ptep_ipte(addr, ptep, 0, 0, IPTE_LOCAL); + } +} + +static inline void ptep_ipte_global(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, int nodat) +{ + unsigned long opt, asce; + + if (MACHINE_HAS_TLB_GUEST) { + opt = 0; + asce = READ_ONCE(mm->context.gmap_asce); + if (asce == 0UL || nodat) + opt |= IPTE_NODAT; + if (asce != -1UL) { + asce = asce ? : mm->context.asce; + opt |= IPTE_GUEST_ASCE; + } + __ptep_ipte(addr, ptep, opt, asce, IPTE_GLOBAL); + } else { + __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL); + } +} + +static inline pte_t ptep_flush_direct(struct mm_struct *mm, + unsigned long addr, pte_t *ptep, + int nodat) +{ + pte_t old; + + old = *ptep; + if (unlikely(pte_val(old) & _PAGE_INVALID)) + return old; + atomic_inc(&mm->context.flush_count); + if (MACHINE_HAS_TLB_LC && + cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id()))) + ptep_ipte_local(mm, addr, ptep, nodat); + else + ptep_ipte_global(mm, addr, ptep, nodat); + atomic_dec(&mm->context.flush_count); + return old; +} + +static inline pte_t ptep_flush_lazy(struct mm_struct *mm, + unsigned long addr, pte_t *ptep, + int nodat) +{ + pte_t old; + + old = *ptep; + if (unlikely(pte_val(old) & _PAGE_INVALID)) + return old; + atomic_inc(&mm->context.flush_count); + if (cpumask_equal(&mm->context.cpu_attach_mask, + cpumask_of(smp_processor_id()))) { + set_pte(ptep, set_pte_bit(*ptep, __pgprot(_PAGE_INVALID))); + mm->context.flush_mm = 1; + } else + ptep_ipte_global(mm, addr, ptep, nodat); + atomic_dec(&mm->context.flush_count); + return old; +} + +static inline pgste_t pgste_get_lock(pte_t *ptep) +{ + unsigned long new = 0; +#ifdef CONFIG_PGSTE + unsigned long old; + + asm( + " lg %0,%2\n" + "0: lgr %1,%0\n" + " nihh %0,0xff7f\n" /* clear PCL bit in old */ + " oihh %1,0x0080\n" /* set PCL bit in new */ + " csg %0,%1,%2\n" + " jl 0b\n" + : "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE]) + : "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory"); +#endif + return __pgste(new); +} + +static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste) +{ +#ifdef CONFIG_PGSTE + asm( + " nihh %1,0xff7f\n" /* clear PCL bit */ + " stg %1,%0\n" + : "=Q" (ptep[PTRS_PER_PTE]) + : "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE]) + : "cc", "memory"); +#endif +} + +static inline pgste_t pgste_get(pte_t *ptep) +{ + unsigned long pgste = 0; +#ifdef CONFIG_PGSTE + pgste = *(unsigned long *)(ptep + PTRS_PER_PTE); +#endif + return __pgste(pgste); +} + +static inline void pgste_set(pte_t *ptep, pgste_t pgste) +{ +#ifdef CONFIG_PGSTE + *(pgste_t *)(ptep + PTRS_PER_PTE) = pgste; +#endif +} + +static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste, + struct mm_struct *mm) +{ +#ifdef CONFIG_PGSTE + unsigned long address, bits, skey; + + if (!mm_uses_skeys(mm) || pte_val(pte) & _PAGE_INVALID) + return pgste; + address = pte_val(pte) & PAGE_MASK; + skey = (unsigned long) page_get_storage_key(address); + bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED); + /* Transfer page changed & referenced bit to guest bits in pgste */ + pgste_val(pgste) |= bits << 48; /* GR bit & GC bit */ + /* Copy page access key and fetch protection bit to pgste */ + pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT); + pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56; +#endif + return pgste; + +} + +static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry, + struct mm_struct *mm) +{ +#ifdef CONFIG_PGSTE + unsigned long address; + unsigned long nkey; + + if (!mm_uses_skeys(mm) || pte_val(entry) & _PAGE_INVALID) + return; + VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID)); + address = pte_val(entry) & PAGE_MASK; + /* + * Set page access key and fetch protection bit from pgste. + * The guest C/R information is still in the PGSTE, set real + * key C/R to 0. + */ + nkey = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56; + nkey |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48; + page_set_storage_key(address, nkey, 0); +#endif +} + +static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry) +{ +#ifdef CONFIG_PGSTE + if ((pte_val(entry) & _PAGE_PRESENT) && + (pte_val(entry) & _PAGE_WRITE) && + !(pte_val(entry) & _PAGE_INVALID)) { + if (!MACHINE_HAS_ESOP) { + /* + * Without enhanced suppression-on-protection force + * the dirty bit on for all writable ptes. + */ + entry = set_pte_bit(entry, __pgprot(_PAGE_DIRTY)); + entry = clear_pte_bit(entry, __pgprot(_PAGE_PROTECT)); + } + if (!(pte_val(entry) & _PAGE_PROTECT)) + /* This pte allows write access, set user-dirty */ + pgste_val(pgste) |= PGSTE_UC_BIT; + } +#endif + set_pte(ptep, entry); + return pgste; +} + +static inline pgste_t pgste_pte_notify(struct mm_struct *mm, + unsigned long addr, + pte_t *ptep, pgste_t pgste) +{ +#ifdef CONFIG_PGSTE + unsigned long bits; + + bits = pgste_val(pgste) & (PGSTE_IN_BIT | PGSTE_VSIE_BIT); + if (bits) { + pgste_val(pgste) ^= bits; + ptep_notify(mm, addr, ptep, bits); + } +#endif + return pgste; +} + +static inline pgste_t ptep_xchg_start(struct mm_struct *mm, + unsigned long addr, pte_t *ptep) +{ + pgste_t pgste = __pgste(0); + + if (mm_has_pgste(mm)) { + pgste = pgste_get_lock(ptep); + pgste = pgste_pte_notify(mm, addr, ptep, pgste); + } + return pgste; +} + +static inline pte_t ptep_xchg_commit(struct mm_struct *mm, + unsigned long addr, pte_t *ptep, + pgste_t pgste, pte_t old, pte_t new) +{ + if (mm_has_pgste(mm)) { + if (pte_val(old) & _PAGE_INVALID) + pgste_set_key(ptep, pgste, new, mm); + if (pte_val(new) & _PAGE_INVALID) { + pgste = pgste_update_all(old, pgste, mm); + if ((pgste_val(pgste) & _PGSTE_GPS_USAGE_MASK) == + _PGSTE_GPS_USAGE_UNUSED) + old = set_pte_bit(old, __pgprot(_PAGE_UNUSED)); + } + pgste = pgste_set_pte(ptep, pgste, new); + pgste_set_unlock(ptep, pgste); + } else { + set_pte(ptep, new); + } + return old; +} + +pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, pte_t new) +{ + pgste_t pgste; + pte_t old; + int nodat; + + preempt_disable(); + pgste = ptep_xchg_start(mm, addr, ptep); + nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT); + old = ptep_flush_direct(mm, addr, ptep, nodat); + old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new); + preempt_enable(); + return old; +} +EXPORT_SYMBOL(ptep_xchg_direct); + +/* + * Caller must check that new PTE only differs in _PAGE_PROTECT HW bit, so that + * RDP can be used instead of IPTE. See also comments at pte_allow_rdp(). + */ +void ptep_reset_dat_prot(struct mm_struct *mm, unsigned long addr, pte_t *ptep, + pte_t new) +{ + preempt_disable(); + atomic_inc(&mm->context.flush_count); + if (cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id()))) + __ptep_rdp(addr, ptep, 0, 0, 1); + else + __ptep_rdp(addr, ptep, 0, 0, 0); + /* + * PTE is not invalidated by RDP, only _PAGE_PROTECT is cleared. That + * means it is still valid and active, and must not be changed according + * to the architecture. But writing a new value that only differs in SW + * bits is allowed. + */ + set_pte(ptep, new); + atomic_dec(&mm->context.flush_count); + preempt_enable(); +} +EXPORT_SYMBOL(ptep_reset_dat_prot); + +pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, pte_t new) +{ + pgste_t pgste; + pte_t old; + int nodat; + + preempt_disable(); + pgste = ptep_xchg_start(mm, addr, ptep); + nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT); + old = ptep_flush_lazy(mm, addr, ptep, nodat); + old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new); + preempt_enable(); + return old; +} +EXPORT_SYMBOL(ptep_xchg_lazy); + +pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, + pte_t *ptep) +{ + pgste_t pgste; + pte_t old; + int nodat; + struct mm_struct *mm = vma->vm_mm; + + preempt_disable(); + pgste = ptep_xchg_start(mm, addr, ptep); + nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT); + old = ptep_flush_lazy(mm, addr, ptep, nodat); + if (mm_has_pgste(mm)) { + pgste = pgste_update_all(old, pgste, mm); + pgste_set(ptep, pgste); + } + return old; +} + +void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, + pte_t *ptep, pte_t old_pte, pte_t pte) +{ + pgste_t pgste; + struct mm_struct *mm = vma->vm_mm; + + if (!MACHINE_HAS_NX) + pte = clear_pte_bit(pte, __pgprot(_PAGE_NOEXEC)); + if (mm_has_pgste(mm)) { + pgste = pgste_get(ptep); + pgste_set_key(ptep, pgste, pte, mm); + pgste = pgste_set_pte(ptep, pgste, pte); + pgste_set_unlock(ptep, pgste); + } else { + set_pte(ptep, pte); + } + preempt_enable(); +} + +static inline void pmdp_idte_local(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp) +{ + if (MACHINE_HAS_TLB_GUEST) + __pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE, + mm->context.asce, IDTE_LOCAL); + else + __pmdp_idte(addr, pmdp, 0, 0, IDTE_LOCAL); + if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m) + gmap_pmdp_idte_local(mm, addr); +} + +static inline void pmdp_idte_global(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp) +{ + if (MACHINE_HAS_TLB_GUEST) { + __pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE, + mm->context.asce, IDTE_GLOBAL); + if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m) + gmap_pmdp_idte_global(mm, addr); + } else if (MACHINE_HAS_IDTE) { + __pmdp_idte(addr, pmdp, 0, 0, IDTE_GLOBAL); + if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m) + gmap_pmdp_idte_global(mm, addr); + } else { + __pmdp_csp(pmdp); + if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m) + gmap_pmdp_csp(mm, addr); + } +} + +static inline pmd_t pmdp_flush_direct(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp) +{ + pmd_t old; + + old = *pmdp; + if (pmd_val(old) & _SEGMENT_ENTRY_INVALID) + return old; + atomic_inc(&mm->context.flush_count); + if (MACHINE_HAS_TLB_LC && + cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id()))) + pmdp_idte_local(mm, addr, pmdp); + else + pmdp_idte_global(mm, addr, pmdp); + atomic_dec(&mm->context.flush_count); + return old; +} + +static inline pmd_t pmdp_flush_lazy(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp) +{ + pmd_t old; + + old = *pmdp; + if (pmd_val(old) & _SEGMENT_ENTRY_INVALID) + return old; + atomic_inc(&mm->context.flush_count); + if (cpumask_equal(&mm->context.cpu_attach_mask, + cpumask_of(smp_processor_id()))) { + set_pmd(pmdp, set_pmd_bit(*pmdp, __pgprot(_SEGMENT_ENTRY_INVALID))); + mm->context.flush_mm = 1; + if (mm_has_pgste(mm)) + gmap_pmdp_invalidate(mm, addr); + } else { + pmdp_idte_global(mm, addr, pmdp); + } + atomic_dec(&mm->context.flush_count); + return old; +} + +#ifdef CONFIG_PGSTE +static int pmd_lookup(struct mm_struct *mm, unsigned long addr, pmd_t **pmdp) +{ + struct vm_area_struct *vma; + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + + /* We need a valid VMA, otherwise this is clearly a fault. */ + vma = vma_lookup(mm, addr); + if (!vma) + return -EFAULT; + + pgd = pgd_offset(mm, addr); + if (!pgd_present(*pgd)) + return -ENOENT; + + p4d = p4d_offset(pgd, addr); + if (!p4d_present(*p4d)) + return -ENOENT; + + pud = pud_offset(p4d, addr); + if (!pud_present(*pud)) + return -ENOENT; + + /* Large PUDs are not supported yet. */ + if (pud_large(*pud)) + return -EFAULT; + + *pmdp = pmd_offset(pud, addr); + return 0; +} +#endif + +pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr, + pmd_t *pmdp, pmd_t new) +{ + pmd_t old; + + preempt_disable(); + old = pmdp_flush_direct(mm, addr, pmdp); + set_pmd(pmdp, new); + preempt_enable(); + return old; +} +EXPORT_SYMBOL(pmdp_xchg_direct); + +pmd_t pmdp_xchg_lazy(struct mm_struct *mm, unsigned long addr, + pmd_t *pmdp, pmd_t new) +{ + pmd_t old; + + preempt_disable(); + old = pmdp_flush_lazy(mm, addr, pmdp); + set_pmd(pmdp, new); + preempt_enable(); + return old; +} +EXPORT_SYMBOL(pmdp_xchg_lazy); + +static inline void pudp_idte_local(struct mm_struct *mm, + unsigned long addr, pud_t *pudp) +{ + if (MACHINE_HAS_TLB_GUEST) + __pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE, + mm->context.asce, IDTE_LOCAL); + else + __pudp_idte(addr, pudp, 0, 0, IDTE_LOCAL); +} + +static inline void pudp_idte_global(struct mm_struct *mm, + unsigned long addr, pud_t *pudp) +{ + if (MACHINE_HAS_TLB_GUEST) + __pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE, + mm->context.asce, IDTE_GLOBAL); + else if (MACHINE_HAS_IDTE) + __pudp_idte(addr, pudp, 0, 0, IDTE_GLOBAL); + else + /* + * Invalid bit position is the same for pmd and pud, so we can + * re-use _pmd_csp() here + */ + __pmdp_csp((pmd_t *) pudp); +} + +static inline pud_t pudp_flush_direct(struct mm_struct *mm, + unsigned long addr, pud_t *pudp) +{ + pud_t old; + + old = *pudp; + if (pud_val(old) & _REGION_ENTRY_INVALID) + return old; + atomic_inc(&mm->context.flush_count); + if (MACHINE_HAS_TLB_LC && + cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id()))) + pudp_idte_local(mm, addr, pudp); + else + pudp_idte_global(mm, addr, pudp); + atomic_dec(&mm->context.flush_count); + return old; +} + +pud_t pudp_xchg_direct(struct mm_struct *mm, unsigned long addr, + pud_t *pudp, pud_t new) +{ + pud_t old; + + preempt_disable(); + old = pudp_flush_direct(mm, addr, pudp); + set_pud(pudp, new); + preempt_enable(); + return old; +} +EXPORT_SYMBOL(pudp_xchg_direct); + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, + pgtable_t pgtable) +{ + struct list_head *lh = (struct list_head *) pgtable; + + assert_spin_locked(pmd_lockptr(mm, pmdp)); + + /* FIFO */ + if (!pmd_huge_pte(mm, pmdp)) + INIT_LIST_HEAD(lh); + else + list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp)); + pmd_huge_pte(mm, pmdp) = pgtable; +} + +pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) +{ + struct list_head *lh; + pgtable_t pgtable; + pte_t *ptep; + + assert_spin_locked(pmd_lockptr(mm, pmdp)); + + /* FIFO */ + pgtable = pmd_huge_pte(mm, pmdp); + lh = (struct list_head *) pgtable; + if (list_empty(lh)) + pmd_huge_pte(mm, pmdp) = NULL; + else { + pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next; + list_del(lh); + } + ptep = (pte_t *) pgtable; + set_pte(ptep, __pte(_PAGE_INVALID)); + ptep++; + set_pte(ptep, __pte(_PAGE_INVALID)); + return pgtable; +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +#ifdef CONFIG_PGSTE +void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, pte_t entry) +{ + pgste_t pgste; + + /* the mm_has_pgste() check is done in set_pte_at() */ + preempt_disable(); + pgste = pgste_get_lock(ptep); + pgste_val(pgste) &= ~_PGSTE_GPS_ZERO; + pgste_set_key(ptep, pgste, entry, mm); + pgste = pgste_set_pte(ptep, pgste, entry); + pgste_set_unlock(ptep, pgste); + preempt_enable(); +} + +void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep) +{ + pgste_t pgste; + + preempt_disable(); + pgste = pgste_get_lock(ptep); + pgste_val(pgste) |= PGSTE_IN_BIT; + pgste_set_unlock(ptep, pgste); + preempt_enable(); +} + +/** + * ptep_force_prot - change access rights of a locked pte + * @mm: pointer to the process mm_struct + * @addr: virtual address in the guest address space + * @ptep: pointer to the page table entry + * @prot: indicates guest access rights: PROT_NONE, PROT_READ or PROT_WRITE + * @bit: pgste bit to set (e.g. for notification) + * + * Returns 0 if the access rights were changed and -EAGAIN if the current + * and requested access rights are incompatible. + */ +int ptep_force_prot(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, int prot, unsigned long bit) +{ + pte_t entry; + pgste_t pgste; + int pte_i, pte_p, nodat; + + pgste = pgste_get_lock(ptep); + entry = *ptep; + /* Check pte entry after all locks have been acquired */ + pte_i = pte_val(entry) & _PAGE_INVALID; + pte_p = pte_val(entry) & _PAGE_PROTECT; + if ((pte_i && (prot != PROT_NONE)) || + (pte_p && (prot & PROT_WRITE))) { + pgste_set_unlock(ptep, pgste); + return -EAGAIN; + } + /* Change access rights and set pgste bit */ + nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT); + if (prot == PROT_NONE && !pte_i) { + ptep_flush_direct(mm, addr, ptep, nodat); + pgste = pgste_update_all(entry, pgste, mm); + entry = set_pte_bit(entry, __pgprot(_PAGE_INVALID)); + } + if (prot == PROT_READ && !pte_p) { + ptep_flush_direct(mm, addr, ptep, nodat); + entry = clear_pte_bit(entry, __pgprot(_PAGE_INVALID)); + entry = set_pte_bit(entry, __pgprot(_PAGE_PROTECT)); + } + pgste_val(pgste) |= bit; + pgste = pgste_set_pte(ptep, pgste, entry); + pgste_set_unlock(ptep, pgste); + return 0; +} + +int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr, + pte_t *sptep, pte_t *tptep, pte_t pte) +{ + pgste_t spgste, tpgste; + pte_t spte, tpte; + int rc = -EAGAIN; + + if (!(pte_val(*tptep) & _PAGE_INVALID)) + return 0; /* already shadowed */ + spgste = pgste_get_lock(sptep); + spte = *sptep; + if (!(pte_val(spte) & _PAGE_INVALID) && + !((pte_val(spte) & _PAGE_PROTECT) && + !(pte_val(pte) & _PAGE_PROTECT))) { + pgste_val(spgste) |= PGSTE_VSIE_BIT; + tpgste = pgste_get_lock(tptep); + tpte = __pte((pte_val(spte) & PAGE_MASK) | + (pte_val(pte) & _PAGE_PROTECT)); + /* don't touch the storage key - it belongs to parent pgste */ + tpgste = pgste_set_pte(tptep, tpgste, tpte); + pgste_set_unlock(tptep, tpgste); + rc = 1; + } + pgste_set_unlock(sptep, spgste); + return rc; +} + +void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep) +{ + pgste_t pgste; + int nodat; + + pgste = pgste_get_lock(ptep); + /* notifier is called by the caller */ + nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT); + ptep_flush_direct(mm, saddr, ptep, nodat); + /* don't touch the storage key - it belongs to parent pgste */ + pgste = pgste_set_pte(ptep, pgste, __pte(_PAGE_INVALID)); + pgste_set_unlock(ptep, pgste); +} + +static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry) +{ + if (!non_swap_entry(entry)) + dec_mm_counter(mm, MM_SWAPENTS); + else if (is_migration_entry(entry)) { + struct page *page = pfn_swap_entry_to_page(entry); + + dec_mm_counter(mm, mm_counter(page)); + } + free_swap_and_cache(entry); +} + +void ptep_zap_unused(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, int reset) +{ + unsigned long pgstev; + pgste_t pgste; + pte_t pte; + + /* Zap unused and logically-zero pages */ + preempt_disable(); + pgste = pgste_get_lock(ptep); + pgstev = pgste_val(pgste); + pte = *ptep; + if (!reset && pte_swap(pte) && + ((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED || + (pgstev & _PGSTE_GPS_ZERO))) { + ptep_zap_swap_entry(mm, pte_to_swp_entry(pte)); + pte_clear(mm, addr, ptep); + } + if (reset) + pgste_val(pgste) &= ~(_PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT); + pgste_set_unlock(ptep, pgste); + preempt_enable(); +} + +void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep) +{ + unsigned long ptev; + pgste_t pgste; + + /* Clear storage key ACC and F, but set R/C */ + preempt_disable(); + pgste = pgste_get_lock(ptep); + pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT); + pgste_val(pgste) |= PGSTE_GR_BIT | PGSTE_GC_BIT; + ptev = pte_val(*ptep); + if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE)) + page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 0); + pgste_set_unlock(ptep, pgste); + preempt_enable(); +} + +/* + * Test and reset if a guest page is dirty + */ +bool ptep_test_and_clear_uc(struct mm_struct *mm, unsigned long addr, + pte_t *ptep) +{ + pgste_t pgste; + pte_t pte; + bool dirty; + int nodat; + + pgste = pgste_get_lock(ptep); + dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT); + pgste_val(pgste) &= ~PGSTE_UC_BIT; + pte = *ptep; + if (dirty && (pte_val(pte) & _PAGE_PRESENT)) { + pgste = pgste_pte_notify(mm, addr, ptep, pgste); + nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT); + ptep_ipte_global(mm, addr, ptep, nodat); + if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE)) + pte = set_pte_bit(pte, __pgprot(_PAGE_PROTECT)); + else + pte = set_pte_bit(pte, __pgprot(_PAGE_INVALID)); + set_pte(ptep, pte); + } + pgste_set_unlock(ptep, pgste); + return dirty; +} +EXPORT_SYMBOL_GPL(ptep_test_and_clear_uc); + +int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, + unsigned char key, bool nq) +{ + unsigned long keyul, paddr; + spinlock_t *ptl; + pgste_t old, new; + pmd_t *pmdp; + pte_t *ptep; + + /* + * If we don't have a PTE table and if there is no huge page mapped, + * we can ignore attempts to set the key to 0, because it already is 0. + */ + switch (pmd_lookup(mm, addr, &pmdp)) { + case -ENOENT: + return key ? -EFAULT : 0; + case 0: + break; + default: + return -EFAULT; + } +again: + ptl = pmd_lock(mm, pmdp); + if (!pmd_present(*pmdp)) { + spin_unlock(ptl); + return key ? -EFAULT : 0; + } + + if (pmd_large(*pmdp)) { + paddr = pmd_val(*pmdp) & HPAGE_MASK; + paddr |= addr & ~HPAGE_MASK; + /* + * Huge pmds need quiescing operations, they are + * always mapped. + */ + page_set_storage_key(paddr, key, 1); + spin_unlock(ptl); + return 0; + } + spin_unlock(ptl); + + ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl); + if (!ptep) + goto again; + new = old = pgste_get_lock(ptep); + pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT | + PGSTE_ACC_BITS | PGSTE_FP_BIT); + keyul = (unsigned long) key; + pgste_val(new) |= (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48; + pgste_val(new) |= (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56; + if (!(pte_val(*ptep) & _PAGE_INVALID)) { + unsigned long bits, skey; + + paddr = pte_val(*ptep) & PAGE_MASK; + skey = (unsigned long) page_get_storage_key(paddr); + bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED); + skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT); + /* Set storage key ACC and FP */ + page_set_storage_key(paddr, skey, !nq); + /* Merge host changed & referenced into pgste */ + pgste_val(new) |= bits << 52; + } + /* changing the guest storage key is considered a change of the page */ + if ((pgste_val(new) ^ pgste_val(old)) & + (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT)) + pgste_val(new) |= PGSTE_UC_BIT; + + pgste_set_unlock(ptep, new); + pte_unmap_unlock(ptep, ptl); + return 0; +} +EXPORT_SYMBOL(set_guest_storage_key); + +/* + * Conditionally set a guest storage key (handling csske). + * oldkey will be updated when either mr or mc is set and a pointer is given. + * + * Returns 0 if a guests storage key update wasn't necessary, 1 if the guest + * storage key was updated and -EFAULT on access errors. + */ +int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr, + unsigned char key, unsigned char *oldkey, + bool nq, bool mr, bool mc) +{ + unsigned char tmp, mask = _PAGE_ACC_BITS | _PAGE_FP_BIT; + int rc; + + /* we can drop the pgste lock between getting and setting the key */ + if (mr | mc) { + rc = get_guest_storage_key(current->mm, addr, &tmp); + if (rc) + return rc; + if (oldkey) + *oldkey = tmp; + if (!mr) + mask |= _PAGE_REFERENCED; + if (!mc) + mask |= _PAGE_CHANGED; + if (!((tmp ^ key) & mask)) + return 0; + } + rc = set_guest_storage_key(current->mm, addr, key, nq); + return rc < 0 ? rc : 1; +} +EXPORT_SYMBOL(cond_set_guest_storage_key); + +/* + * Reset a guest reference bit (rrbe), returning the reference and changed bit. + * + * Returns < 0 in case of error, otherwise the cc to be reported to the guest. + */ +int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr) +{ + spinlock_t *ptl; + unsigned long paddr; + pgste_t old, new; + pmd_t *pmdp; + pte_t *ptep; + int cc = 0; + + /* + * If we don't have a PTE table and if there is no huge page mapped, + * the storage key is 0 and there is nothing for us to do. + */ + switch (pmd_lookup(mm, addr, &pmdp)) { + case -ENOENT: + return 0; + case 0: + break; + default: + return -EFAULT; + } +again: + ptl = pmd_lock(mm, pmdp); + if (!pmd_present(*pmdp)) { + spin_unlock(ptl); + return 0; + } + + if (pmd_large(*pmdp)) { + paddr = pmd_val(*pmdp) & HPAGE_MASK; + paddr |= addr & ~HPAGE_MASK; + cc = page_reset_referenced(paddr); + spin_unlock(ptl); + return cc; + } + spin_unlock(ptl); + + ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl); + if (!ptep) + goto again; + new = old = pgste_get_lock(ptep); + /* Reset guest reference bit only */ + pgste_val(new) &= ~PGSTE_GR_BIT; + + if (!(pte_val(*ptep) & _PAGE_INVALID)) { + paddr = pte_val(*ptep) & PAGE_MASK; + cc = page_reset_referenced(paddr); + /* Merge real referenced bit into host-set */ + pgste_val(new) |= ((unsigned long) cc << 53) & PGSTE_HR_BIT; + } + /* Reflect guest's logical view, not physical */ + cc |= (pgste_val(old) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 49; + /* Changing the guest storage key is considered a change of the page */ + if ((pgste_val(new) ^ pgste_val(old)) & PGSTE_GR_BIT) + pgste_val(new) |= PGSTE_UC_BIT; + + pgste_set_unlock(ptep, new); + pte_unmap_unlock(ptep, ptl); + return cc; +} +EXPORT_SYMBOL(reset_guest_reference_bit); + +int get_guest_storage_key(struct mm_struct *mm, unsigned long addr, + unsigned char *key) +{ + unsigned long paddr; + spinlock_t *ptl; + pgste_t pgste; + pmd_t *pmdp; + pte_t *ptep; + + /* + * If we don't have a PTE table and if there is no huge page mapped, + * the storage key is 0. + */ + *key = 0; + + switch (pmd_lookup(mm, addr, &pmdp)) { + case -ENOENT: + return 0; + case 0: + break; + default: + return -EFAULT; + } +again: + ptl = pmd_lock(mm, pmdp); + if (!pmd_present(*pmdp)) { + spin_unlock(ptl); + return 0; + } + + if (pmd_large(*pmdp)) { + paddr = pmd_val(*pmdp) & HPAGE_MASK; + paddr |= addr & ~HPAGE_MASK; + *key = page_get_storage_key(paddr); + spin_unlock(ptl); + return 0; + } + spin_unlock(ptl); + + ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl); + if (!ptep) + goto again; + pgste = pgste_get_lock(ptep); + *key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56; + paddr = pte_val(*ptep) & PAGE_MASK; + if (!(pte_val(*ptep) & _PAGE_INVALID)) + *key = page_get_storage_key(paddr); + /* Reflect guest's logical view, not physical */ + *key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48; + pgste_set_unlock(ptep, pgste); + pte_unmap_unlock(ptep, ptl); + return 0; +} +EXPORT_SYMBOL(get_guest_storage_key); + +/** + * pgste_perform_essa - perform ESSA actions on the PGSTE. + * @mm: the memory context. It must have PGSTEs, no check is performed here! + * @hva: the host virtual address of the page whose PGSTE is to be processed + * @orc: the specific action to perform, see the ESSA_SET_* macros. + * @oldpte: the PTE will be saved there if the pointer is not NULL. + * @oldpgste: the old PGSTE will be saved there if the pointer is not NULL. + * + * Return: 1 if the page is to be added to the CBRL, otherwise 0, + * or < 0 in case of error. -EINVAL is returned for invalid values + * of orc, -EFAULT for invalid addresses. + */ +int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc, + unsigned long *oldpte, unsigned long *oldpgste) +{ + struct vm_area_struct *vma; + unsigned long pgstev; + spinlock_t *ptl; + pgste_t pgste; + pte_t *ptep; + int res = 0; + + WARN_ON_ONCE(orc > ESSA_MAX); + if (unlikely(orc > ESSA_MAX)) + return -EINVAL; + + vma = vma_lookup(mm, hva); + if (!vma || is_vm_hugetlb_page(vma)) + return -EFAULT; + ptep = get_locked_pte(mm, hva, &ptl); + if (unlikely(!ptep)) + return -EFAULT; + pgste = pgste_get_lock(ptep); + pgstev = pgste_val(pgste); + if (oldpte) + *oldpte = pte_val(*ptep); + if (oldpgste) + *oldpgste = pgstev; + + switch (orc) { + case ESSA_GET_STATE: + break; + case ESSA_SET_STABLE: + pgstev &= ~(_PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT); + pgstev |= _PGSTE_GPS_USAGE_STABLE; + break; + case ESSA_SET_UNUSED: + pgstev &= ~_PGSTE_GPS_USAGE_MASK; + pgstev |= _PGSTE_GPS_USAGE_UNUSED; + if (pte_val(*ptep) & _PAGE_INVALID) + res = 1; + break; + case ESSA_SET_VOLATILE: + pgstev &= ~_PGSTE_GPS_USAGE_MASK; + pgstev |= _PGSTE_GPS_USAGE_VOLATILE; + if (pte_val(*ptep) & _PAGE_INVALID) + res = 1; + break; + case ESSA_SET_POT_VOLATILE: + pgstev &= ~_PGSTE_GPS_USAGE_MASK; + if (!(pte_val(*ptep) & _PAGE_INVALID)) { + pgstev |= _PGSTE_GPS_USAGE_POT_VOLATILE; + break; + } + if (pgstev & _PGSTE_GPS_ZERO) { + pgstev |= _PGSTE_GPS_USAGE_VOLATILE; + break; + } + if (!(pgstev & PGSTE_GC_BIT)) { + pgstev |= _PGSTE_GPS_USAGE_VOLATILE; + res = 1; + break; + } + break; + case ESSA_SET_STABLE_RESIDENT: + pgstev &= ~_PGSTE_GPS_USAGE_MASK; + pgstev |= _PGSTE_GPS_USAGE_STABLE; + /* + * Since the resident state can go away any time after this + * call, we will not make this page resident. We can revisit + * this decision if a guest will ever start using this. + */ + break; + case ESSA_SET_STABLE_IF_RESIDENT: + if (!(pte_val(*ptep) & _PAGE_INVALID)) { + pgstev &= ~_PGSTE_GPS_USAGE_MASK; + pgstev |= _PGSTE_GPS_USAGE_STABLE; + } + break; + case ESSA_SET_STABLE_NODAT: + pgstev &= ~_PGSTE_GPS_USAGE_MASK; + pgstev |= _PGSTE_GPS_USAGE_STABLE | _PGSTE_GPS_NODAT; + break; + default: + /* we should never get here! */ + break; + } + /* If we are discarding a page, set it to logical zero */ + if (res) + pgstev |= _PGSTE_GPS_ZERO; + + pgste_val(pgste) = pgstev; + pgste_set_unlock(ptep, pgste); + pte_unmap_unlock(ptep, ptl); + return res; +} +EXPORT_SYMBOL(pgste_perform_essa); + +/** + * set_pgste_bits - set specific PGSTE bits. + * @mm: the memory context. It must have PGSTEs, no check is performed here! + * @hva: the host virtual address of the page whose PGSTE is to be processed + * @bits: a bitmask representing the bits that will be touched + * @value: the values of the bits to be written. Only the bits in the mask + * will be written. + * + * Return: 0 on success, < 0 in case of error. + */ +int set_pgste_bits(struct mm_struct *mm, unsigned long hva, + unsigned long bits, unsigned long value) +{ + struct vm_area_struct *vma; + spinlock_t *ptl; + pgste_t new; + pte_t *ptep; + + vma = vma_lookup(mm, hva); + if (!vma || is_vm_hugetlb_page(vma)) + return -EFAULT; + ptep = get_locked_pte(mm, hva, &ptl); + if (unlikely(!ptep)) + return -EFAULT; + new = pgste_get_lock(ptep); + + pgste_val(new) &= ~bits; + pgste_val(new) |= value & bits; + + pgste_set_unlock(ptep, new); + pte_unmap_unlock(ptep, ptl); + return 0; +} +EXPORT_SYMBOL(set_pgste_bits); + +/** + * get_pgste - get the current PGSTE for the given address. + * @mm: the memory context. It must have PGSTEs, no check is performed here! + * @hva: the host virtual address of the page whose PGSTE is to be processed + * @pgstep: will be written with the current PGSTE for the given address. + * + * Return: 0 on success, < 0 in case of error. + */ +int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep) +{ + struct vm_area_struct *vma; + spinlock_t *ptl; + pte_t *ptep; + + vma = vma_lookup(mm, hva); + if (!vma || is_vm_hugetlb_page(vma)) + return -EFAULT; + ptep = get_locked_pte(mm, hva, &ptl); + if (unlikely(!ptep)) + return -EFAULT; + *pgstep = pgste_val(pgste_get(ptep)); + pte_unmap_unlock(ptep, ptl); + return 0; +} +EXPORT_SYMBOL(get_pgste); +#endif |